PHOENIX — Former U.S. Rep. Gabrielle Giffords and her husband launched a political action committee aimed at curbing gun violence today, the second anniversary of the Tucson shooting that killed six people and left her critically injured. Giffords and Mark Kelly wrote in an op-ed published in USA Today that their Americans for Responsible Solutions initiative would help raise money to support greater gun control efforts. “Achieving reforms to reduce gun violence and prevent mass shootings will mean matching gun lobbyists in their reach and resources,” they wrote in the column. They said that it will “raise funds necessary to balance the influence of the gun lobby.” The move was hinted at in Kelly’s recent comments that he and Giffords want to become a prominent voice for gun control efforts. The couple last week visited Newtown, Conn., where a gunman opened fire in an elementary school, killing 20 children and six adults in December. They also met with New York City Mayor Michael Bloomberg, a gun control advocate.